1. Field of the Invention
The present invention relates to a system for the safe transmission of messages from sender to receiver and with positive identification of the sender.
The system is of the kind which includes on the transmitter side: a telefax-type message transmitter; and an encryption device for encrypting the telefax transmission signals prior to transmission; and on the receiver side: a decryption device for decrypting incoming signals prior to their reception in a telefax-type message receiving apparatus; and a message enveloping and message bundling arrangement for safe storage of messages received by the receiving telefax apparatus in an enveloped form within a closed casing.
2. Description of the Related Art
It is previously known to transmit messages between sender and receiver with the aid of apparatus, e.g., of the telefacsimile type, either over physical transmission lines or by cordless transmission. Message transmission is effected by inserting into the telefax apparatus on the sender or transmitter side a sheet of paper which bears the messages to be transmitted, this message being converted to signal form by the transmitting telefax apparatus. These signals are transmitted to the receiver side, where the signals are received and converted to printed text on a further sheet of paper, by the receiving telefax apparatus. In its widest meaning, the word "text", as used here, shall be understood to consist not only of words but also of characters, signs of all different kinds, picture material, etc.
It is also known to encrypt the text prior to transmission so as to safeguard the text against "listening" (tapping) of the messages during their route from the transmitter to the receiver, so that the messages cannot be read by unauthorized persons. The messages must then be decrypted back to their original text form on the receiver side, so that the recipient is able to understand the message.
When sending messages by means of telefacsimile apparatus, which are generally available to a large number of people in a working place for instance, there is a risk of transmitted and printed message being distributed or spread in an uncontrolled fashion, which in some cases may be disadvantageous with regard to technical, business/technical or political relationships. For the purpose of eliminating this risk, it is known from U.S. Pat. No. 5,031,379 to use a message enveloping and message gathering arrangement for safe storage of messages received by the telefax apparatus, in an enveloped form within a closed casing connected to the telefax apparatus.
Areas are found in which a greater degree of safety, or security, against "listening" to message transmissions is required than the degree of safety provided by the technique exemplified above. As is known, a signature found on examples of agreements that are transmitted via telefax apparatus do not constitute a valid signature in legal terms. Another area which requires a greater degree of safety, or security, when transmitting message is found within banking systems, for instance. In order to be valid, it is necessary that the person transmitting an order relating to money transaction (concerning cash, shares, etc.) can be sure that the transmission is not listened to (tapped), and also that the receiver can be certain:
1. that listening or eavesdropping has not taken place; PA1 2. that an unauthorized person cannot have availed himself to the order on the receiver side; and PA1 3. that the sender is actually the person stated on the order.
The object of the present invention is to provide a system which will enable messages to be transmitted with the degree of security that is required in the aforementioned extreme cases.